Old adults preserve motor flexibility during rapid reaching

Christian Greve*, Tibor Hortobagyi, Raoul M. Bongers

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

7 Citations (Scopus)
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Abstract

Purpose Our ability to flexibly coordinate the available degrees of freedom allows us to perform activities of daily living under various task constraints. Healthy old adults exhibit subclinical peripheral and central nervous system dysfunctions, possibly compromising the flexibility in inter-joint coordination during voluntary movements and the ability to adapt to varying task constraints.

Method We examined how healthy old (75.4 +/- 5.2 years, n = 14) compared with young adults (24.3 +/- 2 years, n = 15) make use of the available motor flexibility to adapt to physical and dexterity constraints during a rapid goal-directed reaching task. We manipulated physical and dexterity demands by changing, respectively, external resistance and target size. Motor flexibility was quantified by an uncontrolled manifold (UCM) analysis.

Results We found that healthy young and old adults employ similar motor flexibility as quantified by the ratio between goal equivalent and non-goal equivalent variability (V-Ratio) and were similarly able to adapt to increases in physical and dexterity demands during goal-directed rapid reaching (V-Ratio: p = .092; young: 0.548 +/- 0.113; old: 0.264 +/- 0.117). Age affected end-effector kinematics. Motor flexibility and end-effector kinematics did not correlate.

Conclusions The data challenge the prevailing view that old age affects movement capabilities in general and provide specific evidence that healthy old adults preserve motor flexibility during a reaching task. Future studies applying UCM analysis should examine if experimental set-ups limit movement exploration, leaving possible age differences undetected.

Original languageEnglish
Pages (from-to)955-967
Number of pages13
JournalEuropean Journal of Applied Physiology
Volume117
Issue number5
DOIs
Publication statusPublished - May-2017

Keywords

  • Motor control
  • Ageing
  • Motor flexibility
  • Uncontrolled manifold
  • Reaching
  • Task demand
  • AGE-RELATED-CHANGES
  • JOINT ANGLE VARIABILITY
  • FORCE PRODUCTION TASKS
  • WHITE-MATTER CHANGES
  • SENSORIMOTOR ADAPTATION
  • VISUOMOTOR ADAPTATION
  • EFFECT SIZE
  • SYNERGIES
  • COORDINATION
  • POWER

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